diff --git a/Build/AtlasBuildScripts/checkout_Gaudi.sh b/Build/AtlasBuildScripts/checkout_Gaudi.sh
index a536cf4c3b6273dc7f665607b3edd27c644cf613..15851ec1313fd6724f8cc39a2e9b61e2cd9146f7 100755
--- a/Build/AtlasBuildScripts/checkout_Gaudi.sh
+++ b/Build/AtlasBuildScripts/checkout_Gaudi.sh
@@ -18,6 +18,13 @@ usage() {
     echo "    -t branch/tag: Mandatory branch/tag/hash to check out"
     echo "    -s directory: Mandatory source directory to use"
     echo "    -e url: Optional source URL to use for the checkout"
+    echo
+    echo "  This script will allow the environment variables"
+    echo "  Gaudi_URL and Gaudi_REF to override"
+    echo "  other values (even those on the command line)"
+    echo "  If Gaudi_URL is set to 'current' then"
+	echo "  no clone or checkout is done and the working copy"
+	echo "  in the source directory is left untouched."
 }
 
 # Parse the command line arguments:
@@ -52,6 +59,20 @@ while getopts ":t:o:s:e:h" opt; do
     esac
 done
 
+if [ "$Gaudi_URL" != "" ]; then
+	GAUDIURL=$Gaudi_URL
+	echo "Gaudi URL overridden to $GAUDIURL from environment"
+	if [ "$Gaudi_URL" = "current" ]; then
+		echo "Leaving current checkout in place for build"
+		exit 0
+	fi 
+fi
+
+if [ "$Gaudi_REF" != "" ]; then
+	TAGBRANCH=$Gaudi_REF
+	echo "Gaudi ref overridden to $TAGBRANCH from environment"
+fi
+
 # The tag/branch and a source directory must have been specified:
 if [ "$TAGBRANCH" = "" ] || [ "$SOURCEDIR" = "" ]; then
     echo "Not all required arguments were provided!"
diff --git a/Build/AtlasBuildScripts/checkout_atlasexternals.sh b/Build/AtlasBuildScripts/checkout_atlasexternals.sh
index ba9ebadd509ded5bd6220acaf4689984a9867939..a6a6627ed260f44a28670684e2ff881703c244e9 100755
--- a/Build/AtlasBuildScripts/checkout_atlasexternals.sh
+++ b/Build/AtlasBuildScripts/checkout_atlasexternals.sh
@@ -18,6 +18,13 @@ usage() {
     echo "    -t branch/tag: Mandatory branch/tag/hash to check out"
     echo "    -s directory: Mandatory source directory to use"
     echo "    -e url: Optional source URL to use for the checkout"
+    echo
+    echo "  This script will allow the environment variables"
+    echo "  AtlasExternals_URL and AtlasExternals_REF to override"
+    echo "  other values (even those on the command line)."
+    echo "  If AtlasExternals_URL is set to 'current' then"
+	echo "  no clone or checkout is done and the working copy"
+	echo "  in the source directory is left untouched."
 }
 
 # Parse the command line arguments:
@@ -52,6 +59,20 @@ while getopts ":t:o:s:e:h" opt; do
     esac
 done
 
+if [ "$AtlasExternals_URL" != "" ]; then
+	EXTERNALSURL=$AtlasExternals_URL
+	echo "Externals URL overridden to $EXTERNALSURL from environment"
+	if [ "$AtlasExternals_URL" = "current" ]; then
+		echo "Leaving current checkout in place for build"
+		exit 0
+	fi 
+fi
+
+if [ "$AtlasExternals_REF" != "" ]; then
+	TAGBRANCH=$AtlasExternals_REF
+	echo "Externals ref overridden to $TAGBRANCH from environment"
+fi
+
 # The tag/branch and a source directory must have been specified:
 if [ "$TAGBRANCH" = "" ] || [ "$SOURCEDIR" = "" ]; then
     echo "Not all required arguments were provided!"